Ultrasound assisted reactions and Continuous flow reactors.pptx

Introduction
Working principle
Type of sonochemical reaction
Synthetic application
Uses of ultasound

1. Ultrasound assisted reactions and Continuous flow reactors Master of Pharmacy First Year (Sem-II), Department of Pharmaceutical Chemistry, SMT. KISHORITAI BHOYAR COLLEGE OF PHARMACY KAMPTEE Guided by: Shyam W. Rangari Presented by: Nikita Rahangdale

2. Contents Introduction Working principle Type of sonochemical reaction Synthetic application Uses of ultasound

3. INTRODUCTION Sonochemistry is term used describe the effects of ultrasound on chemical reaction. The name is derived from the prefix "SONO" indicating sound paralleling the longer established various techniques as above. Sonochemistry is branch of chemistry dealing with the chemical effects and application of ultrasonic waves i.e. sound with frequencies above 20KHz (20,000 cycles per second )that lie beyond the upper limit of human hearing although frequencies can be extended up to 100MHz that's especially affects on chemical reactivity.

4. Origin of sonochemical effectsSound (ultrasound) is transmitted via waves alternately compress and stretch the molecular structure of the medium through which is process as shown below In figure. Liquids irradiates with ultrasound can produce bubbles. When under the proper condition these bubbles undergo a violent collapse which generates very high pressure and temperature. This process is called cavitation.

5. Working Principle Mechanism Heat / energy generation in Sonochemistry. Generation of ultra sound-High Fregency generatur is needed that Converts the normal main Frequeng 50-60HZ into Frequency Vibration b/w 20-40 KHZ

6. TYPE OF SONOCHEMICAL REACTION Homogeneous liquid phase reaction Heterogeneous solid/liquid phase reaction Heterogeneous liquid/liquid phase reaction

7. Homogeneous liquid phase reaction In the bulk liquid immediately surrounding the bubble where the rapid collapse of Bubble generates shear forces which can produce mechanical effects. In the bubble itself where any species introduced during its formation will be Subjected to extreme condition of temperature and pressure on collapse leading to Chemical effects.

8. 2. Heterogeneous solid/liquid phase reaction Acoustic cavitation can produce dramatic effects on solid in liquid imperfection Or trapped gas can act as the nuclei for cavitation bubble formation on the surface collapse Can the lead to shock waves break the particle apart. cavitation bubble collapse in the liquid Phase near to a particle can produce force into rapid motion

9. 3.Heterogeneous liquid/liquid phase reaction In heterogeneous liquid /liquid reaction cavitation collapse at or near the interface will Causes disruption and mixing resulting in the formation of very fine emulsions.

10. Synthetic application The first report of ' Sonochemical switching' came from Ando et al when suspension of benzyl bromide was treated with alumina supported potassium cyanide in toluene under the stirring condition the reaction provided diphenylmethane as product formed via Friedal -crafts reaction, in contrast under sonic condition benzyl cyanide was formed as the major product.

11. 1.Reformatsky reaction Many research groups have studied the famous Reformatsky reaction under the influence of ultrasound. Zinc, octanal and ethyl bromoacetate gave a 95% yield of the p-hydroxy ester in 5 min at room temperature under sonication as presented in scheme IIIA.1., when compared with 69% after 12 h at 80 °C without sonication .

12. 2. Synthesis of B-lactams In a similar reaction Bose et al have synthesized ẞ-lactams from zinc, ethyl chromoacetate and a diaryl Schiff base in 95% yield within 4 h at room temperature as shown in scheme IIIA.2, the conventional method of refluxing in toluene gives a yield of 60%.

13. Uses of ultrasound 1.Target detection using SONAR -(Sound Navigation and Ranging) 2. Medical applications: - Medicalsonography (ultrasonography) -Acoustic targeted drug delivery -Cleaning teeth in dental hygiene 3. Industrial Applications: -Ultrasonic testing (non-destructive) -Ultrasonic cleaning

14. Continuous flow reactors Reactors A reactor is a vessel or system in which a chemical reaction takes place. Example: -Batch reactors -Continuous flow reactors -Continuous stirred tank reactor -Plug flow reactors -Fixed bed reactors - Fluidized bed reactors The choice of reactor type depends on various factors, including the type of reaction, the reaction rate, the required product yield, and the required reaction conditions.

15. Continuous flow reactor is based on concept of continuous flow, and residence time. The reactant are continuous feed into the reactor and the reactant takes place as the reactant flow through the reactor. The products are simultaneously remove from the reactor resulting in a continuous and steady straight operation. Principle

16. Working:- 1. Feeding of reactant : Constant flow rate maintain constant concentration of reactant with the reactor. 2. Mixing of reactant: To get homogeneous mixture degree of mixing is controlled. 3.Reaction: Reactant mixed reaction occur rate reaction controlled by factor- catalyst, temperature, pressure, concentration of reactant. 4.Collection of product: Flow rate maintain, constant concentration of product. 5. Monitoring and control: Optimal condition, temperature sensor, flow meter, pressure sensor, computer controlled feedback system.

17. Advantages: - Improved Safety: Better control over reaction conditions, reduces the likelihood of accidental exposure to hazardous materials. -Higher Efficiency: The continuous flow of reactants and products allows for better control over reaction parameters like temperature pressure, concentration of reactant and product, easier separation of the products. -Scalability: Flow chemistry is easily scalable, meaning that a small reaction can be easily scaled up to a larger industrial-scale production. -Faster Reactions: Flow chemistry can result in faster reaction times and more rapid product formation,which can save time and resources. -Reduced Waste: The efficient use of reagents and catalysts, fewer byproducts are produced, reducing waste and minimizing the need for purification steps. -Improve product quality: Purity, quality control and check by sensors maximum yield and minimum impurities.

18. Synthetic applications: - Continuous flow synthesis of Diphenhydramine HCl -Continuous flow synthesis of Ibuprofen -Continuous flow synthesis of Telmisartan Continuous flow synthesis of Diphenhydramine HCl

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